Abstract. The article examines the problem of formation of ethnic boundaries in the process of nation-building in Ukraine and the role of memory politics in this process. The analysis is carried out on a theoretical and methodological basis, including research of the theory of the nation and nationalism, issues of ethnicity, imperial issues, memory policy and historical policy in the post-Soviet space. The efforts of Ukraine to implement the policy of memory, its origins and prerequisites are analyzed. The natural character and direction of this activity, conditioned by the specifics of nation-building in the imperial and Soviet periods, is shown. The main directions, elements, and means of implementing the policy of memory are aimed at forming the foundations of the Ukrainian nation, tearing it off from historical Russia and aiming at spreading Russophobic mythology. Special attention is paid to historical politics as a tool for reforming mass consciousness and implanting Ukrainian identity. The researched factual material made it possible to draw several conclusions about the consequences of the implementation of the memory policy. In particular, after decommunization the theme of decolonization gains increasing importance in Ukraine, being aimed at an even more radical division of the Russian and Ukrainian ethnic groups, of their common historical heritage. In general, the politics of memory may be regarded as an important condition and tool for constructing a new border between Russia and Ukraine.